Canning 101

Late last fall, I bought some concord grapes and cobbled together two little jars of freezer grape jelly (or, more accurately, jam) from a recipe in my Better Homes and Gardens cookbook. It was the most amazing grape jam I had ever tasted–not from anything special about the recipe, but just because it looked and tasted like…well, grape jam. And I made it. And when I pulled one of the jars out in February to make a PB&J, it tasted even better. So I told myself that this summer I would learn how to can.

These pears in syrup brought back such clear memories of going to my grandma’s basement to get a jar of pears, pickled mixed vegetables, or tomatoes from a whole room full of beautifully preserved produce. The things we don’t appreciate at 8 years old…

And can, I have.

The process can be really intimidating—there’s a lot of talk about sterilizing and botulism and eek, why bother? Well, first of all, it’s not that scary, it’s mostly just common sense. Then there’s a lot of talk about putting up multiple dozens of quarts, and spending hours over boiling pots. I have no desire to do either of those things, so I just stuck to small batches, mostly four or five 4 ounce jars or a few half pints at a time. These small batches took an hour or so at the most, start to finish (usually my Friday project with whatever fruit I didn’t finish during the week).

These are the basic tips I’ve picked up so far, though I know I still have a lot to learn (and if anyone has any additional tips or advice, please share in the comments!). I thought I’d share while there’s still a little time left to pick up a few pints of berries or quarts of pears and apples so you could try it for yourself.

Selecting jarsYou can find jars at thrift stores and such, but for the sake of expediency, I’ve just been buying them by the box from my local Ace hardware. There are four sizes/shapes that I’ve used so far:

4 ounce—These are the perfect size for me, and are the size I’ve used the most by far. Just enough for several slices of toast or to top a few servings of ice cream, or to give as a gift. I also like them for bringing a handful of nuts or other snacks to work.

8 ounce—I’ve used these for most of the pickling projects I’ve tried this summer, and for one or two larger jars of jam.

16 ounce (pint) wide—I like these the best so far for canning whole tomatoes, and for bringing lunch to work (soup, salads, or just about any kind of leftovers).

16 ounce (pint) standard—These are the most traditional canning jars, and work best for things you don’t want to float too much; I’ve used them for pears and tomatoes so far.

Once I have my jars, I wash them and the rings in my dishwasher (handwashing in hot soapy water works fine too), and handwash the round lids.

Finding a recipeThere are so many resources to choose from, it would be silly to list them all, but generally you just want to choose a reliable source for your recipe. The one I’ve used most frequently this summer is the Food in Jars blog, which has great small-batch recipes and easy to follow instructions and advice.

Preparing jarsMany jam recipes call for (or benefit from) macerating fruit with sugar for half an hour or longer before cooking. While the fruit rests, I get my jars ready by filling my stock pot about half to 3/4 full of water, dropping my trivet in the bottom of the pot, and adding the jars (I can fit five to six 4 or 8 ounce jars in my pot).

The water needs to be high enough that when the jars are full and lids are on, the water will cover them by at least a good inch. Bring the water to a low simmer while you make the jam. This step is primarily to warm the jars to avoid any temperature shock when you add the hot jam; since all of the recipes I’ve made call for processing for at least 10 minutes, it’s not necessary to “officially” sanitize the jars before filling (see this Q&A from the National Center for Home Food Preservation).

In the last five minutes of cooking your jam, add the lids to the barely simmering pot of water. Have rings handy, but don’t heat them.

Testing the jam
There are a few ways to test the readiness of your jam. The plate test, the spoon test, or taking the jam’s temperature (220 degrees is usually the setting point); mostly I’ve come to use the spoon test, but if you’re unsure, the plate test is probably a bit more reliable. Once it’s nearly at the right consistency for you, lower the temperature to just barely simmering.

Processing the jars
Remove the jars one at a time with your rubber-band wrapped tongs and fill them using the funnel; for most recipes you’ll need to leave about ¼ inch of headspace between the top of the jam and the top of the jar. Wipe any stray jam from the mouth of the jar with a clean towel, remove one of the lids from the hot water, center it on the jar, and screw the ring on just until there’s resistance, it shouldn’t be too tight; repeat with remaining jars.

When all jars are filled, return them to the waterbath, top off with water if needed, put the lid on the pot, and bring to a rolling boil. As soon as the water starts boiling, set a timer for 10 minutes. Boil for the full 10 minutes (depending on the recipe, size of jars, and elevation you may need to adjust the time, but good recipes will note any adjustments). If you have any jam left in the pot, but not enough to fill a whole jar, it can still be stored in the fridge for several weeks.

Cooling and testing the seal
When 10 minutes are up, turn off the heat and let jars set another minute or so. Remove jars carefully with the rubber-band-wrapped tongs and set them on a towel to prevent any sudden temperature changes.

Soon you should start hearing some exciting little pings! as the jars seal. Let them set, undisturbed (as in, don’t mess with the rings) while they cool for at least 12 hours –it can take up to 12 hours for jars to fully seal, so don’t get discouraged if they don’t ping immediately, just wait. Ttest the seal by unscrewing the rings and holding the jar by the edge of the lid, it shouldn’t give at all and the lid should be concave. Clean any sticky bits around the jar with warm water and store in a cupboard until you’re ready to enjoy.

Congratulations, you made jam! Marvel over your little jars and look forward to popping open a colorful jar when it’s grey and cold and dreary outside and good fresh fruit is months away.

18 thoughts on “Canning 101”

Christina, this brings back memories of your grandparents farm and how we weeded, picked and then brought goodies home and froze and canned everything. You’re jars look beautiful. It’s just too bad we live so far away.

Great post! I’ve been on the same journey and this is exactly how I’ve been doing things too (except I like to scoop a little of the boiling water into a bowl and just toss the lids in there so I don’t have to go fishing). Your list of jams sounds amazing.

If you see a jar lifter at your Ace Hardware (especially if you have one of those $5 coupons from buying other things with your loyalty card) buy one. They make fishing the filled jars out of the boiling water much easier than the tongs you’re using.